PHILADELPHIA – The Eagles’ defense has broken down in so many ways during the preseason on third downs, penalties and missed assignments that it’s easy to wonder if the unit is any better than it was last season.

The Eagles ranked last in the NFL in pass defense and 29th out of 32 teams in total defense.

The mistakes were evident throughout the most recent preseason game against the New England Patriots on Friday.

That led defensive coordinator Bill Davis to say: “We were structurally unsound as hell. It was guys lining up on the wrong side that hadn’t happened previously.”

The Eagles have given up an average of 39 points and 483.5 yards in the two preseason games, and opponents have converted 62.5 percent of their third downs. The Patriots converted their first seven third downs through the midway point of the second quarter.

Part of it was that Davis was giving younger players like outside linebackers Marcus Smith and Travis Long, and inside linebackers Najee Goode and Emmanuel Acho extended snaps, some of them coming against the Patriots’ starters. And part of it is the emphasis the referees have put on eliminating contact once a receiver is five yards past the line of scrimmage. The Eagles have committed 19 penalties in two games, most of them on defense. At least five more were declined.

Davis showed how that made a difference in the game. On the Patriots’ first possession, cornerback Cary Williams intercepted New England quarterback Tom Brady and returned the ball 77 yards for a touchdown.

On the Patriots’ second possession, Brady’s pass was incomplete on a third-and-3. But a holding penalty was called on Curtis Marsh, giving the Patriots a first down. They ended up driving for a touchdown.

“(Without the penalty), we’re off the field on third down, and (Brady’s) two series are pick-six and three-and-out,” Davis said. “But we get flagged for grabbing cloth, and we had four penalties on that drive. So we’re hurting ourselves. It’s nobody but us that has to fix that. ... We have to stop breaking the rule, basically.”

The Eagles’ uptempo offense, of course, can lead to situations where the defense doesn’t get much of a break in between possessions, especially if the offense goes three-and-out and has to punt the ball.

That explains why the Eagles led the NFL last season in defensive snaps, with 1,150. They allowed their opponent to convert 40.3 percent of their third-down attempts, which ranked 24th in the NFL. The added plays take a toll.

“You’re fatigued to a degree, tired,” Williams said. “You might be in pain, to a degree, because you took so many reps. Those aren’t necessarily excuses. At the end of the day, you’ve still got to go out there and do your job.

“It’s not easy already to defend in this league. It’s not easy to necessarily to be a defenseman on this type of offense. You can be out there for a nine-play drive, and create a turnover and the next thing you know, 45 seconds to a minute (later), you’re right back out there. It’s hard. But I think we’ve got the guys in this room to get the job done.”

The increased penalties are meant to benefit the offense, leading to more scoring and fan excitement. And the Eagles have big cornerbacks like Williams and Bradley Fletcher who like to play a physical style. That makes them susceptible to penalties for contact beyond five yards.

The Eagles said they have to improve while playing within the new rules.

“It’s us, simple as that,” linebacker DeMeco Ryans said. “We have to make the plays on third down, and we can’t have penalties that put us back on the field when we’ve actually gotten a stop. We’re just shooting ourselves in the foot. Once we stop beating ourselves and focus on the other team, then we’ll be better.”

Added Davis: “If you won’t adjust to the rule, you can’t play. We’ll never get off the field.”